Tobacco smoke is the primary cause of lung cancer, cardiovascular disease and premature death, with nearly 5 million people dying each year. Treatments that prevent smoking will have a major impact on global health and are attractive products for commercial development. Nicotine vaccines and antibodies represent an important strategy for preventing nicotine from reaching the brain, although current clinical-stage vaccines are ineffective and for most people the antibody response is weak and short-lived. The challenge of inducing long- lasting antibodies titers requires a better method for presenting nicotine to the immune system. We hypothesize that targeted nicotine delivery to dendritic cells using agonistic mAbs to CD40 combined with a TLR4-based adjuvant will stimulate a superior antibody response. We will modify the rat anti-mouse CD40 mAb 1C10 for studies in mice and optimize its conjugation with derivatized nicotine. Mice will be vaccinated with ?CD40nic formulated with the TLR4-activating adjuvant GLA-SE. Anti-nicotine antibody titers will be benchmarked against mice vaccinated with a traditional vaccine, nicotine-KLH + alum. Vaccine potency will be determined using quantitative measures of antibody function including nicotine sequestration in blood and prevention of a nicotine abstinence response. Phase I SBIR funding will establish proof-of-concept in a relevant model and provide the justification for subsequent IND-enabling studies that will bring an innovative vaccine for smoking cessation into the clinic.